UPDATE 1-Residents flee Islamist insurgent attack on town in northeast Nigeria

(Adds Islamic State claim of responsibility, details)
MAIDUGURI, Nigeria, Jan 16 (Reuters) - Government troops and
several hundred residents have been forced to flee after
Islamist insurgents overran a town in northeast Nigeria in an
attack claimed by Islamic State, security sources said on
Saturday.
Friday's assault on Marte, which lies on Lake Chad in Borno
state, came just two months after residents driven from their
homes by Islamist attacks had returned to the town under a
government programme.
It underscores the precarious security situation in
northeast Nigeria, where Boko Haram and Islamic State West
Africa Province (ISWAP) are active, and the difficulties the
government faces as it tries to return people displaced by the
violence.
Soldiers fled during Friday's assault and Marte remained
under the control of the militants on Saturday, the sources
said.
An unspecified number of wounded people could not be
reached, and it was not immediately clear whether there had been
any deaths. The sources said they believed the insurgents were
part of ISWAP.
An army statement said troops "tactically withdrew" to
defend against a militant attack outside Marte. Troops had
"effectively destroyed" seven gun trucks and "decimated" an
unconfirmed number of attackers, it said.
Islamic State later posted a statement on its Amaq news
channel on Telegram claiming responsibility for the attack.
Without giving further details, it said seven people had
been killed, and one captured, and that its fighters had seized
weapons, ammunition and six four-wheel-drive vehicles, as well
as burning down the army barracks.
Sources from the military and police said most residents had
fled to the nearby Dikwa local government area and to Maiduguri,
Borno's state capital.
"The situation is grim," one said.
On Thursday, five soldiers were killed and 15 others wounded
by a landmine planted by Boko Haram in the remote village of
Chibok in the southern part of Borno, two military sources told
Reuters.